Which is the best definition of a prokaryotic cell? it has a cell wall but lacks a well–defined nucleus and organelles, and its cytoplasm doesn't have much structure.
it contains a membrane–bound nucleus and organelles, and its organelles have specialized duties.
it contains a membrane–bound nucleus, a large central vacuole, a cell wall, a cell membrane, and chloroplasts.

Options:
it has a cell wall but lacks a well–defined nucleus and organelles, and its cytoplasm doesn't have much structure. - this is the correct one!

It contains a membrane–bound nucleus and organelles, and its organelles have specialized duties.
no!, this is false! prokaryotes don't have membrane-bound nucleus!

It contains a membrane–bound nucleus, a large central vacuole, a cell wall, a cell membrane, and chloroplasts. - no!, this is false! prokaryotes don't have membrane-bound nucleus!

so, for this we only needed to know that prokaryotes DON'T have a membrane-bound nucleus (and this is also perhaps their most important property)